Terminal device for electric compressor

ABSTRACT

A terminal device for an electric compressor has a partition wall and a terminal member for supplying electricity to an electric motor for driving a compression mechanism. The partition wall is located between an electric motor-storing section, which stores the electric motor and in which lubricating oil-containing fluid to be compressed is present, and a circuit section for supplying electricity to the electric motor. The terminal member extends through the partition wall in a sealed and insulated manner. An electricity conduction wire at an end of a lead wire for supplying electricity to the electric motor is directly connected to the end of the terminal member which is on the electric motor-storing section side. An insulation cover is provided so as to extend from the electric motor-storing section—side end of the terminal member to an insulation cover tube of the electricity conduction wire of the lead wire for supplying electricity to the electric motor. The terminal device can exhibit high insulation performance even if polyalkylene glycol-based oil is used as lubricating oil-containing fluid to be compressed. Further, the terminal device has a simple structure not requiring a cluster, can ensure high insulation performance, and can be constructed at low cost.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a terminal device for an electriccompressor, and specifically, to a terminal device for an electriccompressor which can change a kind of lubricating oil contained in fluidto be compressed (for example, refrigerant) to a cheap one, and evenwhen the lubricating oil is changed, can ensure good insulationperformance.

BACKGROUND ART OF THE INVENTION

A structure has been known wherein electricity supply to an electricmotor built in an electric compressor is carried out using a sealedterminal device (also called as a hermetic terminal) (for example,Patent document 1). In such a conventional terminal device for anelectric compressor, for example, as depicted in FIG. 5, sealed andinsulated terminal device 104, in which a plurality of terminals 103 areheld by terminal plate 102 so as to extend through the plate 102 at asealed and insulated condition (for example, a sealed and insulatedcondition via glass), is attached at a predetermined position ofcompressor housing 101, to the inner end of each sealed terminal 103 ofthis sealed and insulated terminal device 104, each input femaleterminal 106 of cluster 107, in which a plurality of input femaleterminals 106 are held in resin housing 105, is electrically connectedby fitting, etc., and electricity is supplied to a coil wire for astator of the built-in electric motor through wire for electricitysupply 108 connected to the input female terminal 106.

Further, generally lubricating oil is contained in a fluid to becompressed by a compressor (for example, refrigerant R134a) forlubrication of respective parts of the compressor, etc., and in anelectric compressor built in with an electric motor, because thelubricating oil-containing fluid to be compressed exists in (passesthrough) the electric motor storing section for cooling the built-inelectric motor, etc. and it comes into contact with the electric motorstoring section side of the terminal device, a high insulation propertyis required for this portion. In particular, in the above-describedstructure in which cluster 107 is connected to the inner end of sealedterminal 103, because of presence of the connection structure for theelectricity conductive portions by fitting, etc., many gap portions areformed, therein the lubricating oil-containing fluid to be compressedflows and the insulation property is liable to be reduced, andtherefore, in order to prevent leak and the like through the lubricatingoil, a high insulation property is required. In the conventionalelectric compressor as described above, usually, polyol ester-based oil,which is used generally for electric household appliances and the like,is used as the lubricating oil, and because this polyol ester-based oilhas a relatively high insulation property as oil itself, no problem withrespect to failure in insulation occurs.

Patent document 1: JP-A-2006-42409

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, because the above-described polyol ester-based oil isexpensive, there is a requirement to want to change the lubricating oilto a cheaper one, in particular, to polyalkylene glycol-based oil.However, because the polyalkylene glycol-based oil is low in insulationperformance as compared with the polyol ester-based oil, if the kind ofthe lubricating oil is changed as the conventional cluster terminalstructure as shown in FIG. 5 is left as it is, anxiety with respect toinsulation performance may remain.

Accordingly, an object of the present invention is to provide a terminaldevice for an electric compressor which can exhibit a sufficiently highinsulation performance even in case where polyalkylene glycol-based oilis used as lubricating oil contained in fluid to be compressed, whichcan easily employ a simple structure using no cluster, and which can beconstructed inexpensively while its high insulation performance can beensured.

Means for Solving the Problems

To achieve the above-described object, a terminal device for an electriccompressor according to the present invention has a partition wall whichis located between a storing section for an electric motor for driving acompression mechanism, in which lubricating oil-containing fluid to becompressed is present, and a circuit section for supplying electricityto the electric motor, for isolating the both sections from each other,and a terminal member for supplying electricity to the electric motorwhich extends through the partition wall in a sealed and insulatedmanner, and is characterized in that an electricity conduction wire atan end of a lead wire for supplying electricity to the electric motor isdirectly connected to an end of the terminal member which is on anelectric motor-storing section side, and an insulation cover is providedso as to extend from the electric motor-storing section-side end of theterminal member to an insulation cover tube of the electricityconduction wire of the lead wire for supplying electricity to theelectric motor.

In such a terminal device for an electric compressor, since theelectricity conduction wire at the end of the lead wire for supplyingelectricity to the electric motor (a core wire of the lead wire forelectricity supply) is directly connected to the inner end of theterminal member without using a cluster structure, occurrence ofunnecessary gap portions and the like, into which lubricatingoil-containing fluid to be compressed is liable to enter, is suppressedat this portion, and this portion is constructed in a very simplestructure. By making a cluster unnecessary, it becomes to realize agreat reduction in cost and simplification of structure for the terminaldevice. Further, because of direct connection, a good electricconductivity can be ensured. On the other hand, because naked portionsfor electricity conduction are directly connected to each other, theconnection portion is likely to be exposed to the lubricatingoil-containing fluid to be compressed, and by this, anxiety with respectto insulation performance in the connection portion, especially, withrespect to insulation performance in case where lubricating oil low ininsulation property is used, may remain. In order to solve this anxiety,the insulation cover extending from the electric motor-storingsection-side end of the terminal member to the insulation cover tube ofthe electricity conduction wire of the lead wire for electricity supplyis provided. By providing this insulation cover, the whole of theabove-described connection portion, which has anxiety that the portionmay be exposed to the lubricating oil-containing fluid to be compressed,is covered, and therefore, a high insulation performance may be ensuredfor this portion.

In particular, in case where the above-described insulation cover is aninsulation cover capable of coming into close contact with both of theelectric motor-storing section-side end of the terminal member and theinsulation cover tube, complete isolation of the above-describedconnection portion becomes possible, and a further high insulationperformance may be ensured. As the insulation cover, in consideration ofhandling ability for attachment and close contact ability with theelectric motor-storing section-side end and the insulation cover tube, amaterial having an elasticity is preferably employed, and for example,it is preferred that the insulation cover is formed from a rubber-basedmaterial.

Concrete shape and the like of the above-described terminal member arenot particularly limited, and to aim at simplification of structure andreduction in cost, for example, it is possible to employ a structurewherein the terminal member comprises a bolt-like member capable ofbeing fixed at the electricity-supply circuit section side.

Further, in the terminal device for an electric compressor according tothe present invention, a structure is preferably employed wherein anelectricity conductive portion of the terminal member extending betweenthe above-described both sections is covered with an insulating varnish,and by this, the insulation property of this portion may be also greatlyimproved by the simple structure where the predetermined electricityconductive portion of the terminal member is merely covered with theinsulating varnish. As a result, by together employing theabove-described structure provided with the insulation cover, even incase where polyalkylele glycol-based oil low in insulation performanceis used as the lubricating oil contained in the fluid to be compressed,it becomes possible to exhibit a necessary and sufficiently highinsulation performance more securely.

As the above-described insulating varnish, for example, anelectro-deposition varnish can be used. By using an electro-depositionvarnish, a layer for insulation may be easily formed at a uniformmembrane thickness, and a desired insulation property can be easilyobtained over a desirable range.

As the above-described lubricating oil contained in the fluid to becompressed, for example, it is preferred to use a cheap polyalkyleneglycol-based oil such as one aforementioned. Although the insulationproperty of polyalkylene glycol-based oil itself is lower than that ofpolyol ester-based oil, by the structure of direct connection of theterminal member to the lead wire for electricity supply and the coveringstructure for the connection portion by the insulation cover in thepresent invention, and further by the above-described covering structurewith the insulating varnish, it becomes possible to realize asufficiently high insulation performance easily.

In the terminal device for an electric compressor according to thepresent invention, the above-described partition wall is formed, forexample, by a compressor housing. Further, it is also possible that thecompressor housing is formed in an open-type structure, the openingportion of the compressor housing is tightly closed by a lid member, forexample, by a lid member also functioning as a support member for theelectricity supply circuit section, and a function of theabove-described partition wall may be given to this lid member.

Further, although the terminal device for an electric compressoraccording to the present invention can be applied to any electriccompressor requiring improvement of insulation performance andsimplification of the structure for the terminal device portion, inparticular, it is suitable for a compressor used in an air conditioningsystem for vehicles which is manufactured at a mass production style andwhich is required to be reduced in cost as a whole and for whichreduction in cost of used lubricating oil is strongly required.

Where, the electric compressor in the present invention includes aso-called hybrid compressor which has a first compression mechanismdriven only by an external drive source (for example, an engine for avehicle or an electric motor for vehicle running) and a secondcompression mechanism driven only by a built-in electric motor in asingle compressor and in which the first compression mechanism and thesecond compression mechanism are driven selectively or simultaneously,in addition to an electric compressor incorporating therein only anelectric motor as a drive source for a compression mechanism. In case ofthe hybrid compressor, the present invention can be applied to aterminal device for the built-in electric motor.

Effect According to the Invention

In the terminal device for an electric compressor according to thepresent invention, since the end of the lead wire for electricity supplyto the electric motor is directly connected to the inner end of theterminal member, it is not necessary to use a cluster structure using aconventional terminal member made of copper, it becomes possible togreatly reduce cost of the terminal device by greatly simplifying thestructure of this portion, and because the whole of the above-describedconnection portion is covered with the insulation cover, a sufficientlyhigh performance can be ensured for the connection portion in which theelectricity conduction portion is liable to be exposed, and therefore,while simplification in structure and reduction in cost are achieved, anecessary and sufficiently high insulation performance can be maintainedeven in case where polyalkylene glycol-based oil low in insulationperformance is used as the lubricating oil contained in the fluid to becompressed.

BRIEF EXPLANATION OF THE DRAWINGS

[FIG. 1] FIG. 1 is vertical sectional view showing an example of anelectric compressor applied with a terminal device for an electriccompressor according to the present invention.

[FIG. 2] FIG. 2 is a schematic sectional view of a connection portion ofa terminal member used in the terminal device for an electric compressordepicted in FIG. 1 with a lead wire for electricity supply.

[FIG. 3] FIG. 3 is a schematic sectional view of a connection portion ofa terminal member with a lead wire for electricity supply, showinganother example different from that depicted in FIG. 2.

[FIG. 4] FIG. 4 is a schematic side view of a terminal member showing anexample being provided with an insulating varnish.

[FIG. 5] FIG. 5 is a schematic diagram of a conventional terminaldevice.

EXPLANATION OF SYMBOLS

-   1: electric compressor-   2: fixed scroll-   3: movable scroll-   4: compression mechanism-   8: compressor housing-   9: electric motor-   10: rotational shaft-   11: stator-   12: rotor-   13: electric motor storing section-   14: side wall of compressor housing as partition wall-   15: terminal device-   16: circuit section for electricity supply-   17: terminal member for electricity supply-   18: lead wire for electricity supply-   19: insulation cover tube-   20: coil wire for stator-   21: caulked portion-   22: additional insulation cover tube-   23, 24: insulation cover-   25: insulating varnish

THE BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, desirable embodiments of the present invention will beexplained referring to the drawings.

FIG. 1 depicts an example of an electric compressor applied with thepresent invention, FIGS. 2-4 show examples of the portions of terminalmembers of a terminal device in case where the present invention isapplied to the electric compressor. In FIG. 1, symbol 1 indicates thewhole of the electric compressor, electric compressor 1 has a scrolltype compression mechanism 4 comprising a fixed scroll 2 and a movablescroll 3, and a fluid to be compressed (for example, refrigerant R134a)sucked from a suction chamber 5 is compressed in compression mechanism4, and thereafter, it is discharged into a discharge chamber 6. Movablescroll 3 is driven by a rotational shaft 10 of an electric motor 9 builtin a compressor housing 8 so as to achieve an orbital movement relativeto fixed scroll 2 via a crank mechanism 7. Electric motor 9 comprises astator 11 and rotor 12, and rotational shaft 10 is rotated integrallywith rotor 12. The fluid to be compressed contains lubricating oil whichis polyalkylene glycol-based oil, and this lubricating oil-containingfluid to be compressed is passed also through a storing section 13 forthe built-in electric motor 9.

A terminal device 15 is provided on a side wall 14 of compressor housing8, and a predetermined electricity is supplied to electric motor 9through terminal device 15 from a circuit section for electricity supply16 connected to an external power source (not shown). This electricitysupply is performed through a terminal member for electricity supply 17to electric motor 9, which extends through a partition wall (in thisembodiment, side wall 14 of compressor housing 8) that is locatedbetween storing section 13 for electric motor 9 for driving thecompression mechanism present with the lubricating oil-containing fluidto be compressed and circuit section for electricity supply 16 toelectric motor 9 and that isolates the both sections, and a lead wirefor electricity supply 18 for electric motor 9 connected to the innerend of terminal member 17 (the electric motor storing section-side end).The core wire of lead wire for power supply 18 extends toward stator 11so as to form the coil of stator 11 of motor 9.

The portion of the above-described terminal member 17 is structured asdepicted in FIGS. 2-4. In the example depicted in FIG. 2, theabove-described terminal member 17 is formed as a bolt-like membercapable of being fixed at the side of electricity supply circuit section16. To the inner end of this terminal member 17 (the electric motorstoring section-side end), the end of lead wire for electricity supply18, in particular, the end of coil wire 20 for stator 11 of electricmotor 9, which is the core wire (electricity conduction wire) of leadwire for electricity supply 18 covered with insulation cover tube 19, isconnected, for example, by caulking at a caulked portion 21. In theexample depicted in FIG. 3, an additional insulation cover tube 22 isfurther covered on the above-described insulation cover tube 19 in orderto further enhance the insulation property, and similarly to theabove-described structure, the end of coil wire 20 of stator 11 isconnected at caulked portion 21 by caulking.

Such an electric connection portion formed by caulked portion 21 iscovered with insulation covers 23, 24 as depicted in FIGS. 2 and 3.Insulation covers 23, 24 are formed from a rubber-based material, andthey are provided so as to extend from the electric motor storingsection-side end of terminal member 17 to insulation cover tubes 19, 22for the electricity conduction wire of lead wire for electricity supply18 and so as to come into close contact with both sides. By thestructure where insulation covers 23, 24 are brought into close contactwith both of the electric motor storing section-side end of terminalmember 17 and insulation cover tubes 19, 22, the above-describedelectric connection portion is completely covered, and the connectionportion is securely insulated from the lubricating oil contained in thefluid to be compressed which is present in the electric motor storingsection side.

Further, in this embodiment, as depicted in FIG. 4, the electricityconduction portion of terminal member 17 extending between the bothsections of electric motor storing section 13 and circuit section forelectricity supply 16 is covered with insulating varnish 25 comprisingan electro-deposition varnish, and the outer surface of terminal member17 in this zone is completely insulated from the circumferences.Therefore, particularly, in the inner end-side portion of and itsvicinity of terminal member 17 can be maintained at a necessary andsufficiently high insulation performance, by this structure togetherwith the above-described insulation structure due to insulation covers23, 24, even if polyalkylene glycol-based oil low in insulationperformance is used as the lubricating oil contained in the fluid to becompressed.

Further, by the structure where the end of lead wire for electricitysupply 18 to electric motor 9 is directly connected to the inner end ofterminal member 17, it becomes unnecessary to use a cluster structure,and simplification of the structure of this portion and reduction incost of the terminal device also become possible at the same time.Namely, in addition to realization of a desired high insulationperformance, simplification of the structure and reduction in cost ofthe terminal device are achieved.

INDUSTRIAL APPLICATIONS OF THE INVENTION

The terminal device for an electric compressor according to the presentinvention can be applied to any electric compressor incorporatingtherein an electric motor, and in particular, it is suitable for acompressor used in an air conditioning system for vehicles which ismanufactured at a mass production style and which is required to bereduced in cost as the whole of the compressor and for which reductionin cost of used lubricant is required.

1. A terminal device for an electric compressor having a partition wallwhich is located between a storing section for an electric motor fordriving a compression mechanism, in which lubricating oil-containingfluid to be compressed is present, and a circuit section for supplyingelectricity to said electric motor, for isolating said both sectionsfrom each other, and a terminal member for supplying electricity to saidelectric motor which extends through said partition wall in a sealed andinsulated manner, characterized in that an electricity conduction wireat an end of a lead wire for supplying electricity to said electricmotor is directly connected to an end of said terminal member which ison an electric motor-storing section side, and an insulation cover isprovided so as to extend from said electric motor-storing section-sideend of said terminal member to an insulation cover tube of saidelectricity conduction wire of said lead wire for supplying electricityto said electric motor.
 2. The terminal device for an electriccompressor according to claim 1, wherein said insulation cover is aninsulation cover capable of coming into close contact with both of saidelectric motor-storing section-side end of said terminal member and saidinsulation cover tube.
 3. The terminal device for an electric compressoraccording to claim 1, wherein said insulation cover is formed from arubber-based material.
 4. The terminal device for an electric compressoraccording to claim 1, wherein said terminal member comprises a bolt-likemember capable of being fixed at a side of said electricity-supplycircuit section.
 5. The terminal device for an electric compressoraccording to claim 1, wherein an electricity conductive portion of saidterminal member extending between said both sections is covered with aninsulating varnish.
 6. The terminal device for an electric compressoraccording to claim 5, wherein said insulating varnish is anelectro-deposition varnish.
 7. The terminal device for an electriccompressor according to claim 1, wherein a polyalkylene glycol-based oilis used as said lubricating oil.
 8. The terminal device for an electriccompressor according to claim 1, wherein said partition wall is formedby a compressor housing.
 9. The terminal device for an electriccompressor according to claim 1, wherein said electric compressor is acompressor used in an air conditioning system for vehicles.